Bail flaw detector cab



June 2, 1936. J, E N Y nun rmw DETECTOR CAR Original Filed Nov. 4, 1933 T MIL JOINT IWICA TING AIICIllN/SM TD FLA M I [OPENJ UELANTY ttomeg Reissued June 2 1936 UNITED STATES PATENT OFFICE Sperry Products, Inc.

Brooklyn, N. D ration oi. New York Y., a 'cor- Original No. 2,027,814, dated January 14, 1936,

Serial No. 696,660, November 4, 1933. Application tor reissue Mai-ch24, 1936, Serial No.

13 Claim.

This invention relates to rail fiaw detector mechanisms the type employed in the Sperry grail fiaw detector cars. As is now well known. isaid Sperry rail fiaw detector mechanism operiates on the principle of sending current through Jthe rail to establish an electromagnetic field surirounding the same and then detecting any variations in the said electromagnetic field by means of induction coils which will respond to any variations in fiux caused by regions of flaw.

Since in passing over rail joints the irregularities in the current path set up by the joint-bars, bolts, etc. cause distortion of the electromagnetic field, such regions of electromagnetic flux distor- V tion would be picked up by the induction means in the same manner as an internal fissure within the rail. In order to avoid picking up these indications at every rail joint there are provided joint gcutout mechanisms, such as shown in the patent f to H. C. Drake. No.' 1,912,569 granted June 6, 1933, g'which cutout mechanisms operate to cause the Zfiaw indicating means to be rendered ineffective =as long as the induction means is passing over a joint and which also operate a joint-indicating mechanism at the same time.

It is the principal object or my invention to provide another form or joint-cutout mechanism operating on an entirely different principle irom that hefetolore'employed.

Further objects and advantages 01' my invention will become apparent in the following detailed description.

In the accompanying drawing,

Fig. 1 is aside view of a portion of a Sperry rail fiaw detector mechanism showing my invention applied thereto.

Fig. 2 is a plan view of a railat the Joint, showing substantially the eiiective operating range of the Joint-cutout mechanism.

Fig.3isawiringdiagramillustratingthe principle embodied in my invention.

Fig. 4 is a perspective view showing one of my Joint-cutgutrmembers in operative position with respectfto a rail ioint.

Fig.5isaviewsimi1arto1 'ig.3butshowinga modified form- 01' the invention.

Referring first to Fig. 1 oi' the drawing, there is illustrated a portion or the car both ill ot'a Sperry rail fiaw detector car. Within the car body is pomtioned a generator G which is designed tosupplycurrcnttotheraiibymeansoisets oibrushes il, i2 carried by a current brush carriage II. Said currenthmsh carriage maybe supported on the rail by means .such as flanged wheels llandsaidcarriageisnormal lyheldin raised position out of engagement with the rail by..means such as retractile springs (not shown) and cables i1. To lower the current brush carriage to effective position in engagement with the rail there may be supplied fluid pressure cylinders iii to which fluid pressure is adapted to be supplied to depress pistons having piston rods l9 connected to the current brush carriage.

The current sent through the rail from generator G by way oi. brushes ,1! establishes an electromagnetic field surrounding the rail R and said field will be uniform influx intensity along the rail as long as no fiaw isllocated therein. When a flaw is located within the rail the electromagnetic field is distorted. Such distortion is detected by means of induction coils 20 which may be housed in a suitable. housing 2i and supported on a detector carriage 22 which is in turn supported on the current brush carriage by means such as a loosely fitting bolt 23 and springs 24; constituting limited universal joints which permit the'detector carriage to move independently of the current brush carriage. The detector carriage may be supported on the rail by means such as rollers 25.

It will now be seen that as the car travels along the rails the detector coils 20 will cut a constant number of lines 01' force but that as soon as a region 01' flaw is encountered one of said coils will cut a difi'erent number of lines of force and a diflerentiai E. M. l". will be generated. Fluctuations in the current supply will have no efiect upon the inductive means It becausesaid means comprises a pair of coils of equal inductive efi'ect and oppositely connected, so that fluctuations in the current supply aflect both coils equally, oppositely, and simultaneously.

when the detector mechanism 20 reaches a rail Joint it obviously reaches a region oi electromagnetic distortion, since such joint, as shownin Figs. 2 and 4, comprises joint bars Ill as well as bolts and other mechanisms, not shown. Such electromagnetic distortion ordinarily would be Picked up by the detector In It and would actuate an indicator in a similar manner as would a flaw. Thus, at every rail Joint a series of indications would come through caused by the irregularities in the electromagnetic flux introduced by the rail Joint mechanism. To obviate this condition, Sperry cars havebeen equipped with Joint cutout fingers as shown in-the said patent to Drake No. 1,912,569, which flnzets slide along the-side of the rail-and ensure the Jointbars to actuate the fingers and close circuits which serve to do two things. First. they open the circuit to indicating mechanism so that the indicating mechanism will be rendered inefiective during the passage 01 the detector mecha-' nism over the rail joint, and, secondly, they close the circuit through a rail joint-indicating mecha nism to give an indication of the occurrence of a joint. It will be apparent from the said patent that the form of joint cutout therein employed called for mechanical engagement of moving members with the joint-bars and'this introduced certain difliculties in operation which it is one purpose of my invention to overcome. For example, the flngers had to be adjusted for various types of joint-bars some of which projected be yond the rail to a diii'erent degree from others. Also, various projections on the rail, such as de tached portions, sometimes operated the fingers. I have therefore provided for a non-contacting joint-cutout mechanism which will not engage the Joint-bar and hence will be free of the operating difficulties which have been experienced with the contacting type of Joint cutout.

My invention embodies a magnetic circuit which normally has an air gap and which air gap is designed to be partially occupied by the Jointbar of a rail joint. Thus, for instance, in Fig. 4, I have shown two induction coils 40, 4| in magnetically coupled relation. Said coupling may include opposed L-shaped cores 42 and 3 to form three sides cl a circuit, the fourth side joining the bases of the coils being normally an air gap. The coils and 4| are housed in a suitable housing which may be suspended from the detector carriageby supports 46, so that said coils normally are positioned adjacent the side 01' the rail. 0n approaching a joint, the joint-bar will be in position to furnish the closing side of thegmagnetic circuit, thus reducing the air gap.

Since the metal of the joint-bar furnishes a path 0! higher magnetic permeability for the magnetic flux, the reluctance oi the magnetic circuit is reduced, and I utilize the said reduction in reluctance to open the circult'oi the indicating mechanism and to close the circuit to the rail joint mechanism. For this purpose, I make the magnetic circuit a. part oi. an oscillatory circuit so that when the reluctance of the magnetic circuit is reduced by the presence of a Joint-bar,

more energy will be ied back into the oscillatory circuit, thus increasing the current in the plate circuit of a vacuum tube of the oscillatory circuit. The E. M. F. generated in the coils connected to the oscillator may be utilized as the starting impulse for initiating oscillation. The output from the plate SI of the tube Bil is fed back through the magnetic circuit, including coils 40 and II, into the grid i2 01 said tube to set up the oscillation. Increase 01 the current inthe plate circuit of the vacuum tube, as by the average value of oscillation, will increase the current flowing through a relay 30 in the plate circuit. which relay willthen attract its armatures BI, 65 to open the circuit to the flaw indicating mechanism at and to close thecircuit to the rail Joint indicating mechanism at contact 58.

Since the coils in housing 45 will have passed beyond the joint-bars ill, as shown in dotted lines in Fig. 2, before the detector mechanism 20 has passed beyond said joint-bars, it is necessary to provide some means for continuing to render the flaw indicating mechanism inefl'ective until the detector mechanism 20 has passed beyond the angle-bars. For this purpose, I provide a duplicate mechanism '45 supported on the detector carriage by support 46' at the rear 01 the detector the coils of the first circuit leave the joint-bar the search unit is still on the joint-bar but by this unit comprising the coils 20 has passed a predemechanism, whereas the housing 45 is positioned the required distancein advance of said mecha-i nism. When relay is energized due to the fact that coils 4n and u have reachedthe joint-bar said relay not only renders the flaw indicating mechanism ineflective but also attracts an arms-i ture to close a circuit at 56 which short-cir-i cults the grid 12 ofa vacuum tube 10 and thus prevents the rear tube Hi from setting up an oscillatory circuit. As soon as the forward coils in: housing 45 have passed beyond the angle-bar'ai predetermined. distance, the average currentthrough relay 60 is reduced, the armature 65 is released, 'and the short-circuit through grid 12 is broken to permit an oscillator)! circuit to be set up through tube 10. Within the rear housing 45', are two induction units 40 and ll similar to thosei in the forward housing and similarly positioned with respect to the angle-bar. They are also connected in the oscillatory circuit between the plate 1| and grid I2 of tube Hi so that when the oscillatory circuit through vacuum tube 10 is allowed to be set up by the release of armature 65, relay will be energized to attract armature 9| to keep the flaw indicating mechanism inefiectitve until the housing 45 has passed beyond the Joint-bars by the required distance. The coils of the first circuit are placed ahead 01 the search unit so as to cut out the pens a predetermined distance before the search unit reaches the Joint-bar. when time the second oscillatory circuit has reached the joint-bar and therefore the flow indicating mechanism continues to be ineflective until the search termined distance beyond the Joint-bar.

Instead of providing a second housing 48' with a second oscillatory circuit including another pair of magnetically coupled coils, I may provide only the first oscillatory circuit and the first housing 45 in advance of the search coils. However, since as explained above, the housing 45 will have passed beyond the joint-bars when the search unit is still over said bars, and it is not desired to have the flaw indicating mechanism rendered eflfective until the search unit has passed beyond the joint-bars, I may substitute for the relay" a delayed-action relay 00' which, in spite of the fact that the housing II has passed beyond the joint-bars to reduce the current in the oscillatory circuit, will remain energized by 1 reason or the fact that it is of the delayed-action type and this will keep armature Ii attracted for '3 a sumcient lengthjot time to insure that the search unit has passed beyond the Joint-bars. The delayed-action relay may be of the type having a band of copper OI surrounding it which intmduces the lag in tie-energizing but which permits the relay to be quickly energized.

The pairs of coils 40, ll being arranged. with 5; their axes parallel to the axis or current will not be affected by current surges through the rail. This is true even where the axis of current becomes distorted because any inductive eflect on i? one coil is counteracted by the simultaneous ei- 3 feet on the other coil acting on the plate and grid of the oscillator tube. i

In accordance with the provisions of the patent i statutes, I have herein described the principle: and operation of my invention, together with the apparatus which I now consider to represent the 2 best embodiment thereof, but I desire to have it understood that the apparatus shown is only 11- g lustratlve and that the invention can be carried 1 Jut by other equivalent means. Also, while it Is designed to usethe various features and elements in the combination and relations described, some of these may be altered and others omitted without interfering with the more general results Jutiined, and the invention extends to such use.

Having described my invention, what I claim and desire to secure by Letters Patent is:

1. In a rail flaw detector mechanism, means responsive to flaws, an indicator, means whereby said indicator is actuated by said responsive means, the rails being joined by joint-bars, and means for rendering said actuating means ineffective when said responsive means passes over a rail joint, said last-named means comprisingan oscillatory circuit and means whereby said circuit is varied by said joint-bars.

2. In a rail flaw detector mechanism, means responsive to flaws, an indicator, means whereby said indicator is actuated by said responsive means, therails being Joined by joint-bars, and means for rendering said actuating means ineffective when said responsive means passes over a rail joint, said last-named means comprising an oscillatory circuit including a magnetic circuit and means whereby said joint-bars change the reluctance of said magnetic circuit.

3. In a rail flaw detector mechanism, means responsive to flaws, an indicator, means whereby said indicator is actuated by said responsive means, the rails being joined by joint-bars, and means for rendering said actuating means inefdective when said responsive means passes over in rail joint, said last-named means comprising Ean oscillatory circuit including an oscillating tube ,Ehavinga feed-back from the plate to the grid, 8. ,imagnetic circuit connected between the plate and Egrid of said tube, and means whereby said joint- ;bars change the reluctance of said magnetic circuit to vary said feed-back.

4. In a rail flaw detector mechanism, means responsive to flaws, an indicator, means whereby said indicator is actuated by said responsive means, the rails being joined by joint-bars, and means for rendering said actuating means inef- Iiective when said responsive means passes over a rail joint, said last-named means comprising an iosciilatory circuit including a normally open mag- 'netic circuit, said Joint-bars being adapted to complete said magnetic circuit to change the reluctance thereof. I

5. In a rail flaw detector mechanism, means responsive to flaws, an indicator, means whereby said indicator -is actuated by said responsive means, the rails being joined by Joint-bars, and means for rendering said actuating means ineffective when said responsive means passes over a rail joint, said last-named means comprising an 'oscillatory circuit normally out of oscillation and means whereby said circuit is set into oscillation when said responsive means is in cooperative relation with said joint-bars.

6. In a rail flaw detector mechanism, means responsive to flaws, an indicator, means whereby said indicator is actuated by said responsive means, the rails being Joined by joint-bars, and means for rendering said actuating means inefiective when said responsive means passes over a rail joint, said last-named means comprising a pair of oscillatory circuits in advance and to the rear of said responsive mom, and means whereby each of said circuits is varied by i joint-bars, said circuits beinx pfllmbned so that said rear circuit cooperates with acid Joint-bars when said forward circuit has passed beyond said Joint-bars.

'7. In a rail flaw detector mechanism, means responsive to flaws, an indicator, means whereby said indicator is actuated by said responsive means, the rails being joined by joint-bars, and means ior'rendering said actuating means inefiective when said responsive means passes over a rail joint, said last-named means comprising a pair of oscillatory circuits in advance and to the rear of said responsive means, means whereby each of said circuits is varied by said joint-bars, said circuits being positioned so that said rear circuit cooperates with said joint-bars when said forward circuit has passed beyond said joint-bars. and means whereby said forward circuit when cooperating with said joint-bars renders said rear circuit ineffective.

8. In a rail flaw detector mechanism, means responsive to flaws, an indicator, means whereby said indicator is actuated by said responsive means, the rails being joined by Joint-bars, and means for rendering said actuating means inefiective when said responsive means passes over a rail Joint, said last-named means comprising a pair of oscillatory circuits in advance and to the .rear of said responsive means, means whereby each of said circuits is varied by said Joint-bars, said circuits being positioned so that said rear circuit cooperates with said joint-bars when said forward circuit has passed beyond said Joint-bars, and means rendered eifective by variations in said oscillatory circuit for rendering said actuating means ineflfective. 9. In a rail flaw detector mechanism, means responsive to flaws, an indicator, means including an electric circuit whereby said indicator is actuated by said responsive means, the rails being Joined by Joint-bars, and means for rendering said actuating means ineflective when said responsive means passes over a rail Joint, said lastnamed means comprising an oscillatory circuit, means wherebysaid oscillatory circuit is varied by said joint-bars, and means rendered effective by variations in said oscillatory circuit for breaking the electric circuit of said indicatoractuating means.

10. In a rail flaw detector mechanism, means responsive to flaws, an indicator, means including an electric circuit whereby said indicator is actuated by said responsive means, the rails being joined by joint-bars, and means for rendering said actuating means ineifective when said responsive means passes over a rail ,ioint, said lastnamed means comprising an "oscillatory circuit, means whereby said oscillatory circuit is varied by said joint-bars, and a relay rendered effective by variationsin said oscillatory circuit for breaking the electric circuit of said indicatorso actuating means.

11. In a rail flaw detector mechanism, means responsive to flaws, an indicator, means including an electric circuit whereby said indicator is actuated by said responsive means, the rails being Joined by joint-bars, and means for rendering said actuating means ineifective when said responsive means passes over a rail Joint, said lastnamed means comprising an oscillatory circuit positioned in advance of said responsive means, means whereby saidosciliatory circuit is varied by said Joint-bars, and a delayed action relay rendered eflective by variations in said oscillatory circuit of said indicator-actuating means for maintaining said circuit open until said responsive means has passed beyond said said indicator-actuating meansin'efl'ective, said iast-named means including delayed action means for maintaining said indicator-actuating means ineflective after said cooperative means has passed out of cooperative relation with the respective joint-bar and until said responsive means has passed beyond said Joint-bar.

'iaooi 13. In a rail flaw detector mechanism, means. responsive to flaws, an indicator, means including; an electric circuit whereby said indicator is ac-fl tuated by said responsive means, the rails beingi joined by- Joint-bars, means positioned in ad-; vance of said responsive means and adapted to cooperate with said joint-bars, and means whereby said cooperative means when in cooperative relation with a joint-bar renders said circuit inetlective.- said last-named means including a delayed action relay for maintaining said circuit in-; effective after said cooperative means has passed out oi cooperative relation with the respective ioint-bar and until said responsive means has passed beyond said joint-bar.

IDEEN J. DBLANTY. 

